Electric meter.



\ v No. 796,036. -PATENTED AUG; 1, 1905.

" T. DUNCAN.

ELECTRIC METER; APPLICATION FILED JULY 3, 1901.

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No. 796,036. PATENTED AUG. 1, 1905.

'T. DUNCAN.

ELECTRIC METER. j APPDICATIOFIILED JULY a,1ao1.

2 SHEETSSHEET 2.

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' UNrrnn STATES PATENT OFFICE.

THOMAS DUNCAN, OF CHICAGO, ILLINOIS.

ELECTRIC METER.

Specification of Letters Patent.

Patented Aug. 1, 1905.

Application filed July 3, 1901. Serial No. 66,954:-

To all whom it may concern;

,measuring the power in systems of electrical distribution, and has asits salient features, first, the provision of step-by-step adjustingmeans, whereby the rate of operation of the meter for a given load maybe varied, whereby the meter may be caused to totalize at a rateaccording to the price agreed .upon with the consumer, the'meter thusconstituting a prediscount meter; second, the provision ofautomatically-operated means for governing the rate of operation of themeter, whereby the meter may be caused to operate at different rates ofspeed according to the load, whereby-the consumer may be charged at anincreased rate for current that is intermittently consumed above anormal maximum, this automatically-operated means preferably including agraded or step-by-step device for effecting a step-by-step increaseinthe torque of the meterthat is, as the excess in load increases thenormal torque is correspondingly increased to produce a rate ofregistration per unit of energy or load of the meter that is greaterthan that which would exist if the current being measured were withinnormal limits; third, means whereby the consumer may be informed of thecurrent consumed in excess of the normal maximum, and means also fordetermining the amount of current consumed within the normal limits.

Various consumers may be allowed diflerent rates of discountthat is, themeters when provided with scales indicating kilowatthours or othermeasuring units may be caused to register different amounts for a givenquantity of current, which is a way of affording consumers theirrespective discounts. I am enabled by means of my invention to have theoperation of the meter adjusted in a man.- ner to have the meterindicate that which the consumer is to be charged for. The readingscalemay, if desired, be marked to indicate the kilowatt-hours, the adjustingmeans being provided to produce an operation of the the counting-trainof the instrument that need not necessarily indicate the exact energy orload, but the quantity of energy 'or load that the consumer is to becharged for, the reading indicating the total actual power consumed lessthe prearranged discount. For example, the meters may be equipped withstep -bystep adjusting devices providing for five, ten, fifteen, twenty,and twenty-five per cent. discount. One consumer may not-be given anydiscount. His meter will then indicate the true reading inkilowatt-hours of the energy consumed. Another consumer may be givenfive per cent. discount. Supposing that he has consumed one thousandkilowatt-hours, his instrument will indicate a charge for nine hundredand fifty kilowatthours. Another consumer, who uses ten thousand or morekilowatt-hours, may be given ten per cent. discount, and for the tenthousand kilowatt-hours consumed his meter will indicatea charge fornine thousand kilowatt-hours. By this arrangement the keeping ofaccounts is greatly simplified, as the consumers are charged accordingto the readingsof their meters, each instrument then taking cognizanceof the particular consumers discount. In the preferred embodiment of myinvention I practice this feature thereof by adjusting the torque of theinstrument, which may be done by including, where the commutatedmotor-meter is employed, a stepby-step resistance in series withthearmature, the greater the discount the greater the resistance includedin circuit with the armature to produce a lesser torque for a given loadand a correspondingly slower operation of the counting mechanism.

That feature of my invention which relates to the automatic change inthe rate of speed of the meter for loads in excess of normal maximum isof particular utility where motors are frequently stopped and startedas,for. example, when such motors are employed in hoisting. As the startingof motors nec essarily requires increased amounts of cur rent,especially where induction-motors are employed, larger units arenecessary at the generating or central station when such motors arefrequently stopped and started than would be required if the motors rancontinuously after once being started. On this account the cost ofinstalling and maintaining the generating apparatus has been greaterheretofore for that service where the motors are frequently stopped andstarted in proportion to the amount of money returned than in othersystems of translating devices to which energy is supplied.

By means of my invention the meter may register a definite percentage ofincreased charge above the normal maximum that is exceeded whenever themotors are started, supposing, for example, that a motor requires anormal maximum of one hundred amperes. In starting or under suddenfluctuation of the load this normal load may be exceeded. When thisexcess occurs, automatic means are brought into operation for increasingthe torque of the meter to cause the same to register at an increasedrate per unit of energy or load. If the excess of current should bestill further increased beyond a predetermined point, the torque may bestill further increased beyond that torque that would merely record theactual power consumed. There may be a business arrangement, for example,whereby the consumers meter has its rate of registration increased fiveper cent. for an increase in the current of five per cent. over thenormal maximum, has its rate of registration increased ten per cent. foran increase in the current of seven and one-half percent. over thenormal maximum or has its rate of registration increased fifteen percent for an increase in the current of ten per cent. over the normalmaximum, &c. In order that the producer and consumer may know what extrademands have been placed upon the system, two reading-scales arepreferably provided in combination with automatic means, which meansengages the normal countingtrain with the rotating element of the meterwhen the current is within normal limits and connects the remaining orabnormal counting-train with the rotating element of the meter when thecurrent is in excess of the normal maximum. This means may indicate tothe consumer the relative efficiency of motors in his service. Inpracticing these features of my invention a solenoid is preferablyincluded in the working circuit, which solenoid may servewhen thecurrent passing therethrough is increased above the normal maximum, asupon the sudden starting of a motor, to close circuit through anothersolenoid that thereupon disconnects the normal measuring mechanism fromthe rotating element of the meter and connects this rotating elementwith the abnormal measuring mechanism. A definite amount of resistanceis at the same time out out from a series connection in thearmature-circuit by a switch controlled by the solenoid to increase thetorque a corresponding percentage in excess of the normal torque.

I will explain my invention more fully by reference to the accompanyingdrawings, in which Figure 1 illustrates a system of direct-currentdistribution, the meter being diagrammatically indicated in elevation.Fig. 2 is also a view of a system of direct-current distribution, thecounting-train being illustrated in detail, the dial-plate beingremoved. Fig. 3 is a plan view of the excess-rate switch and thesolenoid governing the same.

Like parts are indicated by similar characters of reference throughoutthe figures.

I have illustrated a system of direct-current distribution and acommutated motor-meter; but the invention is equally applicable to othersystems of electrical distribution and to meters of other forms.

In Figs. 1 and 2 the generator 1 supplies current to thetransmission-mains 2 2. T hese mains convey current to translatingdevices, such as motors, a motor 3, of well-known type, beingillustrated in Fig. 1, this motor being connected in circuit withsupply-conductors 4 4. A meter 5 is associated with the consumerssupply-circuit 4 4c, the meter in this instance employing afield-winding divided into coils 6 6 in series with one of theconductors 4:, and an armature 7 in bridge between the mains 4 4, acommutator 8 with brushes 9 9 being provided for including the armaturein circuit. The armature is moun ted upon a shaft 10, at the lower partof which is a damping-disk 11, arranged within the fields of thepermanent magnets 12 12 to secure requisite damping effect.

In order to adjust the torque of the meter to conform to the prearrangedcost of the current, I preferably include a resistance 13, that may betermed a discount resistance, in series with the armature, thisresistance being provided with a plurality 'of discountbuttons that maybe suitably marked to indicate various discounts. A switch-arm 14 may beswung into engagement with any of the buttons to include more or less ofthe resistance 13 in circuit with the armature. 1f the consumer is topay at the highest rate, the circuit conditions may be such that none ofthe resistance 13 should beincluded in circuit with the armature,whereby the greatest torque may exist between the armature and field. Ifthe consumer is to receive five per cent. discount, a certain section ofthe resistance may be included in circuit by swinging the rheostat-arm14: to the button marked 5. If the consumer is to receive ten per cent.discount, the arm 14 may be swung to the button 10. Thus the torque ofthe meter may be readily adjusted to cause the meter to indicate aquantity of energy for which a fixed rate may be charged, the indicatedquantity of energy being the same as the actual quantity consumed whereno discount is allowed and less thanthe actual energy consumed accordingto the percentage of discount.

The meter is also provided with a torqueadjusting resistance 15, dividedinto sections having terminal-contacts 16. This resistance is designedto be altogether included, preferably, in serieswith the armature duringthe presence of normal current in the system. As the current in thesystem is increased beyond the normal maximum this resistance 15 is cutout of circuit step by step as the excess current increasescorrespondingly, whereby the torque between the armature and field ofthe meter is increased step by step to cause a corresponding rate ofincrease of the normal torque of the meter. The means that 1 preferablyemploy for accomplishing this result comprises a solenoid orelectromagnet 17, that is included in series with the translating means3, the core of the solenoid being provided with an arm 18, i

that forces the spring-terminals 16 together as the core of the solenoidis drawn into the helix thereof, the attraction of the helix of thesolenoid for its core increasing as the abnormal current wlthin thedistribution-clrcuit lncreases. For example. 1f the meter 51s designedto operate normally when the 'current' remains within the normal maximumof one hundred amperes and if the current exceeds this value by live percent. the, core of" the solenoid will be drawn sufficiently within itshelix to bring the two upper resistance-ter-. minals 16 into contact,thereby cutting out "the first section of the resistance 15 and cansingan-increase of five per cent. in the normal torque of the meter, wherebythe rate of registration' per unit of energy is increased. If thecurrent in the distribution-circuit should increase seven and one-halfpercent. above this normal, then the three upperresistance-' terminals16 are brought into contact'upon a further attraction of thesolenoid-core, whereby the two upper sections of the resistance 15 areshort-circuited and anlincrease of ten per cent. in the normal torque ofthe meter ef- 4 fected. Thus the sections of the resistance 15 aresuccessively cut out or shunted. out of circuit as the current increasesabove the maximum, thereby increasing the strength of the armature-fieldand the torque of the meter. The core of the solenoid is preferablyadjusted by means of'springs 19 to prevent the same from being drawnwithin the solenoid-helix 1while normal current only is present upon theI prefer to record the excess rate upon a diiferen'tcounting mechanism,and on this account 1 provide each meter with two counting-trains 20 and21, the counting-train 2O constituting the normal counting-train, whilethe counting-train 21 constitutes the abnormal counting-train. Aregistering-wheel 22 is permanently geared to the upper end of .themeter-shaft, a pinion 23 being fixed with relation to the gear 22. Thepinion 23 is in constant engagement with a gear 24:, to which gear isrigidly secured a plDlOIl 25.

wheels 24 and 25 are mounted upon ashaft that is rotatably securedwithin a rotating frame 26, the frame being rotatable'about an axiscoincident with an axis of the wheels 22' Theand 23, whereby the wheel'24! is maintained in engagement with the wheel 23 irrespective of therotary adjustmentof the frame. The pinion 25 in the alternative positionillustrated in'Fig. 2 servesto .actuate the counting-train 20, whichcondition exists when the current in the distribution-circuit is normal.When the current is abnormal, by means of mechanism to be hereinafterset forth, the

frame 26 is rotated in a clockwise direction to tuting one terminal of acircuit, including the solenoid or electromagnet 28, the other terminalof this circuit comprising the arm 18,

the energizing-circuit being preferably in bridge of the mains 4 4:.When an abnormal current is upon the line, the circuit including .thesolenoid 28 is closed and the core of this .solenoid is drawn-within thehelix thereof,

and the core byb ei'ng attached-to the swinging frame 26 thereuponcauses a clockwise rotation of the frame to effect an engagement betweenthe pinion.25 and the countingstrain 21. When'there is no longerabnormal current in the working circuit, the helix of the solenoid 17 issufficiently deenergized to permit the springs 19 to withdraw thesolenoidcore, whereupon the circuit including the solenoid 28 is opened,so that the spring 29 may rotate the frame 26 in a contra-clockwisedirection to reengage the pinion 25 with the normal counting-train 20.

Extraneous resistances 30 and 31 may beincluded in circuit,respectively, with the armature and the solenoid helix 28 to reduce thecurrentconsu med by these elements.

It Will be seen that I haveprovided at the district of consumption ameter having thereat a torque-modifying resistance in series with one ofits windings, which in direct current or commutate'd meters is thearmature-winding. This torque-modifying resistance by being in'bridge.in the mains obviates the employment'of a special conductor extendingfrom the generating-station to the district of distribution as hashitherto been proposed.

A block of insulating material 32 may be provided upon the uppermostterminal springv 16 to avoid. electrical connection between thecircuits, including the solenoid 28 and the armature.

In Fig. 3 I have shown an enlarged detail View of the solenoid 17 andits arm 18 and the spring-contacts 27 and 16 actuated thereby.

The solenoid 17 and the element 18 actuated thereby constitute a unitaryelectromagnetic means for modifying the speed-Varying resistance 27,said resistance and said unitary electromagnetic means constituting aunitary means for regulating the rate of speed of the meter per unit ofload or energy.

The prediscount resistance shown in this application formssubject-matter of my application Serial No. 67,814, filed July 11, 1901.

While I have herein shown and particularly described the preferredembodiment of my invention, it is obvious that changes may be readilymade without departing from the spirit thereof, and I do not, therefore,wish to be limited to the precise disclosure herein set forth; but,

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination with a system of electricaldistribution, of a meter having current and pressure windings receivingcurrent therefrom, a graduated resistance, and unitary electromagneticmeans operated by the current in the working circuit for including moreor less of the resistance-sections in circuit with a winding of themeter to vary the torque thereof to change the rate of operation of themeasuring element of the meter per unit of energy or load, substantiallyas described.

2. The combination with a system of electrical distribution, of a meterreceiving current therefrom, unitary automatically-operated step-by-stepadjusting means for changing step by step the rate of operation of themeasuring element of the meter per unit of energy or load, and meanswhereby the aforesaid means are prevented from operating until apredetermined normal maximum of current in the working circuit has beenpassed, substantially as described.

3. The combination with a system of electrical distribution, of a meterreceiving current therefrom, unitary electromagnetic means governed bythe current in the system and serving to automatically step by stepchange the rate of operation of the measuring element of the meter perunit of energy or load, and means whereby the aforesaid means areprevented from operating until a predetermined normal maximum of currentin the working circuit has been passed, substantially as described.

4E. The combination with a system of electrical distribution, of a meterhaving current and pressure windings receiving current therefrom, aresistance, unitary electromagnetic means operated by the current in theworking circuit for including step by step more or less of theresistance in circuit with a winding of the meter to vary the torquethereof to change the rate of operation of the measuring element of themeter per unit of energy or load, and means whereby the aforesaid meansare prevented from operating until a predetermined normal maximum ofcurrent in the working circuit has been passed, substantially asdescribed.

5. The combination with a system of electrical distribution, of a meterhaving current and pressure windings receiving current therefrom, aresistance, and unitary electromagnetic means operated by the current inthe working circuit for including step by step more or less of theresistance in circuit withv a winding of the meter to vary the torquethereof to change the rate of operation of the measuring element of themeter per unit of energy or load, the said resistance being in circuitwith the pressure-winding, substantially as described.

6. The combination with a system of electrical distribution, of a meterhaving current and pressure windings receiving current therefrom, aresistance, unitary electromagnetic means operated by the current in theworking circuit for including step by step more or less of theresistance in circuit with a winding of the meter to vary the torquethereof to change the rate of operation of the measuring element of themeter per unit of energy or load, the said resistance being in circuitwith the pressure-winding, and means whereby the aforesaid means areprevented from operating until a predetermined normal maximum of currentin the working circuit has been passed, substantially as described.

7 The combination with a system of electrical distribution, of a meterreceiving current therefrom having two counting-trains, a rocking framefor connecting one or the other of the counting-trains with the rotatingelement of the meter, an electromagnet for swinging the rocking frame, asolenoid or magnet governed by the current in the system for closingcircuit through the aforesaid magnet to rotate the frame and bring therotating element of the meter out of engagement with one counting-trainand into engagement with the other, and means whereby the said solenoidis prevented from operating until the current of the system has reacheda predetermined normal maximum, substantially as described.

8. The combination with a system of electrical distribution, of ameasuring instrument receiving current therefrom, a prcdiscountadjustingrheostat in series with a meter-winding, a second speed-adjustingrheostat in series with the said discount-rheostat and saidmeter-winding, a solenoid or electromagnet 17 receiving current from thesystem, the latter rheostat having terminals, the said electromagnetbeing provided with means for connecting the said terminals tosuccessively shortcircuit sections of the corresponding rheostat,whereby the torque of the instrument is increased as the currentincreases to increase the rate of registration of the meter per unit ofenergy or load, and means for preventing the said electromagnet fromoperating until the current in the system has passed a predeterminednormal maximum, substantially as described.

9. The combination with a system of electrical distribution, of ameasuring instrument receiving current therefrom, a speed-adjustingrheostat in series with a windingof the meter, a solenoid orelectromagnet 17rec'e1v mg current from the system, the said rheostathaving terminals,the said electromagnet being provided with means forconnecting the said terminals to successively short-circuit the sectionsof the rheostat, whereby the torque of the instrument is increased asthe current intrical distribution, of a measuring instrument havingfield and armaturewindings receiving current therefrom, aspeed-adjusting rheostat in series with the armature-winding, a solenoidor electromagnet 17 receiving currentfrom the system, the said rheostathaving terminals, the said electromagnet being provided with means forconnecting the said terminals to successively short-circuit the sectionsof the rheostat, whereby the torque of the instrument is increased asthe current increases to increase the rate of registration of the meterper unit of energy or load, and means for prev'entingthe saidelectromaguet from operating until the current in the system has passeda predetermined normal maximum, substantially as described.

11. The combination with a system of electrical distribution, of a meterreceiving current therefrom, said meter being provided with twocounting-trains, one to register the load on the system when the currentis with-' in normal limits, and the other to register the load on thesystem when the current exceeds the normal maximum, a swinging frameprovided with gearing for engagement with one I or the other of thecounting-trains, an electromagnet 28 in engagement with the swingingframe, means for engaging the gearing upon the swinging frame with therotating element of the meter, a switc r closing circuit throughthe'magnet 2 magnet 17 for operating the said switch to close the saidcircuit when the current exceeds'the normal maximum to rotate the frame26 to effect engagement between the rotating element of the meter andthe abnormal counting-train, and means whereby the said frame is rotatedin an opposite direction to engage the rotating element ofv the meterwith the normal counting-train when the magnet 28 is deenergized,substantially as described.

12. The combination with a system of electrical distribution, of a meterreceiving current therefrom, said meter being provided with twocounting-trains, one to register the load on the system when the,current is within normal limits, and the other to register the load onthe system when the current exceeds the normal maximum, a swinging frame.provided with gearing for engagement with one or the otherof thecounting-trains, an electromagnet 28 in engagement with the swingingframe, means for engaging the gearing upon the swinging frame with therotating element of the meter, and means whereby the said electromagnetmay be operated upon an increase in current above the normal maximum, toconnect the rotating element of the meter with the abnormalcounting-train, substantially as described.

13. The combinationwith a systemof electrical distribution, of anenergy-meter having two relatively stationary sets of countingtrams,shifting gearing for connecting the ro tating element of the meter withone or the other of the said sets to operate the same, and

means governed by the current inthe system, for operating the aforesaidgearing to bring one or the other of the said counting-trains intooperative engagement with the rotating element of the meter,substantially'as de scribed.

14:- The combination with a system of electrical distribution, of awattmeter located at the district ofconsumption, a to rquemodifyingadjusting resistance in circuit with the pressure-winding of thewattmeter included in a conductor located at the district ofconsumption, and unitary electromagnetic mechanism in the workingcircuit for controlling step by step the operation of the adjustingresistance, substantially as described.

. 15. The combination with a system of eleo- .ance, and unitaryelectromagneticmechanism in the working circuit for controlling step bystep the operation of the adjusting resistance, substantiallyasdescribed. v

16. The combination with a system of elec trical distribution, of acommutated wattmeter located .at the district of consumption, thepressure-winding of the meter constituting the armature of the meter, atorque-modifying adjusting resistance at the district of con sumptionfor the pressure-winding of the meter, .and a bridge-conductor betweenthe distributiOn-mains and located at the district of consumption forsupplyingv the said pressurewinding and resistance with current whichcurrent may be thus modified by said resistance, and unitaryelectromagnetic mechanism in the Working circuit for controlling step bystep the operation of the adjusting resistance, substantially asdescribed.

17. The combination with a system of electrical distribution, of aWattmeter located at the district of consumption, a torque-modifyingadjusting resistance in circuit with the pressure-Winding of theWattmeter included in a conductor located at the district ofconsumption, and unitary electromagnetic mechanism subject to thecurrent of the system for governing the adjusting resistance step bystep, substantially as described.

18. The combination with a system of electrical distribution, of awattmeter located at the district of consumption, a torque-modifyingadjusting resistance at the district of consumption for thepressure-Winding of the meter, a bridge-conductor between thedistribution-mains and located at the district of consumption forsupplying the said pressure- Winding and resistance With current Whichcurrent may be thus modified by said resistance, and unitaryelectromagnetic mechanism subject to the current of the system governingthe torque-modifying resistance step by step, substantially asdescribed.

19. The combination with a system of electrical distribution, of acommutated wattmeter located at the district of consumption, thepressure-winding of the meter constituting the armature of the meter, atorque-modifying adjusting resistance at the district of consumption forthe pressure-winding of the meter, a bridge-conductor between thedistribution-mains and located at the district of consumption forsupplying the said pressurewinding and resistance with current whichcurrent may be thus modified by said resistance, and unitaryelectromagnetic mechanism subject to the current of the system governingthe torque-modifying resistance step by step, substantially asdescribed.

In Witness whereof I hereunto subscribe my name this 23d day of May, A.D. 1901.

TH OMAS DUNCAN.

Witnesses:

' GEORGE L. CRAGG,

HERBERT F. OBERGFELL,

